A particle is moving in a straight line. At time t, the distance between the particle from its starting point is given by x = t - 6t2 + t3. Its acceleration will be zero at
t = 1 unit time
t = 2 unit time
t = 3 unit time
t = 4 unit time
The value of 2, 6, 10 ... (4n - 6)(4n - 2) is equal to
C(2n, n)
(n + 1)(n + 2)(n + 3) ... (2n)
n! P (2n, n)
None of above